Infrared imaging devices have been developed based on MEMS (microelectromechanical systems) technology.
In an uncooled infrared imaging device capable of downsizing and on-chip implementation, in order to increase the infrared detection sensitivity, it is important to thermally isolate the infrared detecting section from the surroundings to increase the thermoelectric conversion efficiency.
For instance, Patent Document 1 (Japanese Patent No. 3715886) discloses a configuration of a thermal infrared solid-state imaging device. In this configuration, the infrared detecting section is supported by a support leg above a recess formed in a silicon substrate. To reduce the thermal conductivity of an interconnection layer on the support leg, the interconnection layer includes a material having high specific resistance. However, even if such a technique is used, the infrared detection sensitivity is insufficient, and there is room for improvement.